使用变量名称键将项目添加到字典python [英] adding item to dictionary python with a variable name key

问题描述

我从项目列表中列出了n个长度的可能组合列表，现在我想创建一个字典，其中每个键都是可能组合列表中的一个项目，因此我可以开始计算每个组合在一组观测值中发生了多少次(对关联规则引擎进行编程的早期阶段).这是我所拥有的:

I made a list of lists of possible combinations of n length from a list of items, and now I want to create a dictionary where each key is one of the items from list of lists of possible combinations, so I can start counting how many times each combination occurs in a set of observations (early stages of programming an association rules engine). Here's what I have:

import itertools
stuff=(1,2,3,4)
n=1
combs=list()
while n<=len(stuff):
    combs.append(list(itertools.combinations(stuff,n)))
    n = n+1
print combs
viewers={'Jim':(1,3,4), 'Bob':(1,2,4), 'Jerry':(1,4), 'Ben':(2), 'Sal':(1,4)}  
showcount={}
for list in combs:
    for item in list:
        showcount["%s",%(item)]=0
print viewers
print showcount

如何使该项目显示为字典中的键?因此，例如，我希望组合'(1,2,4):0'是一个键值对，以便以后可以计算'(1,2,4)'出现的次数.我对Python很陌生，但是我一直在寻找答案，却找不到答案.抱歉，我已经找不到了.

How do I get the item to appear as the key in the dictionary? So for example, I'd like the combination '(1,2,4):0' to be a key value pair so I can later count the number of times '(1,2,4)' appears. I'm pretty new to Python, but I did seach around for an answer and couldn't find one. Apologies if this has been answered and I just couldn't find it.

推荐答案

您可以使用元组作为键:

You can use tuples as keys:

mydict = { (1, 2, 4): 0 }

如果您想数数，请查看 collections.Counter ，它使计数变得微不足道，无需将键初始化为0:

If you want to count things, take a look at collections.Counter, it makes counting trivial, no need to initialize the keys to 0:

counts = collections.Counter()
counts[(1, 2, 4)] += 1

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